Fine structure and function of the gut epithelium of pike eel larvae

Abstract

The development of the alimentary canal of pike eel, Muraenesox cinereus, that were hatched and reared in the laboratory, was examined. The larvae did not feed on zooplankton or phytoplankton and survived for 10 days. Histological and histochemical investigations showed that the alimentary canal was morphologically and functionally differentiated in 3 days after hatching and before exhaustion of the yolk. The foregut was not functional in absorption. The midgut absorptive cell was characterized by a well-developed lamellar membranous structure in the basal portion of the cytoplasm. Na + -K + ATPase activity was demonstrated on the lamellar membrane of the structure. It suggests that water and solute transport is quite active in the midgut epithelium. Orally administered HRP (horseradish peroxidase) was ingested and intracellularly digested in the hindgut absorptive cells. Some of the HRP was transported, without complete digestion, into tissue spaces under the epithelium. Evidence suggests that pike eel larvae possibly utilize dissolved organic matter, including soluble macromolecules, as their nutrition sources. 1995 The Fisheries Society of the British Isles

Morphometric and Histological Changes in Cyprinid Loach, Misgurnus anguillicaudatus, in the Early Growth Period

“…At this time, although the mucosal fold in the midgut is not formed, microvilli structures can be detected in the midgut with optical microscopy and the active absorption of horseradish peroxidase was detected in these cells. Thus, liquefactive nutriments are presumed to be absorbed at this time ( Otake et al, 1995 ). The midgut of the cyprinid loach is already present when it hatches and grows gradually to 50 DPH.…”

Comparative Analysis of Histological Changes in Ussurian Bullhead, Leiocassis ussuriensis, and Korean Bullhead, Pseudobagrus fulvidraco, in the Early Period of Growth

“…However, in the juvenile pike eel, Muraenesox cinereus , the absorptive function of the midgut epithelium begins at 3 DPH, before the complete absorption of the yolk sac. Although the mucosal fold of the midgut has not formed at this time, the microvillous structures are detectable in the midgut with optical microscopy, and the active absorption of horseradish peroxidase is detectable in these cells, so liquefactive nutriments can be absorbed at this time ( Otake et al, 1995 ). As soon as the Ussurian bullhead and Korean bullhead hatched, their midguts were already present and grew gradually to 50 DPH.…”

Absorption of dissolved and dispersed nutrients from sea‐water byPanulirus japonicusphyllosoma larvae

“…The ability to absorb POM or DOM has been reported in many marine invertebrates and also in the larval forms of some vertebrates ( Stephens & Schinske 1961; Jørgensen 1966; Pequignat 1966, 1973; Otake et al . 1993 , 1995). The absorptive mechanisms are diverse and range from absorption through the epithelium of the digestive tract and integument to the creation of feeding currents and the presence of specialized organs for the collection of microscopic food particles and dissolved organic matter.…”

“…For this purpose, larvae of different stages were immersed in seawater containing horseradish peroxidase (HRP), peanut oil, cholesterol and saccharose, and the variations induced by these substances in the internal structures were qualitatively analysed; in particular, the signs of absorption of nutrients and nourishment. These substances were chosen to represent the major nutrient groups (carbohydrates, lipids, and proteins) and some have been employed as tracers of nutrient absorption in experiments with echinoderms (e.g., peanut oil; Pequignat 1966) and fish (e.g., HRP; Watanabe 1984; Otake et al . 1995 ).…”